Abstract A 7‐year‐old, 520‐g, entire, male, long‐tailed chinchilla ( Chinchilla lanigera ) was presented with a 1‐week history of generalised subcutaneous oedema, polyuria and polydipsia. The animal had previously been diagnosed with hypertrophic cardiomyopathy and treated with enalapril, which was discontinued 2 years prior. Clinical examination revealed diffuse oedema most pronounced around the testicles and paws, accompanied by tachypnoea and cachexia. Complete blood count, biochemistry and urinalysis revealed no abnormalities. Advanced imaging, including thoracic radiographs, abdominal ultrasound and echocardiogram, identified bicavitary effusion with no other clinically significant findings. Computed tomography performed under general anaesthesia provided no additional diagnostic information. Thoracocentesis with cytological analysis revealed a modified transudate consistent with inflammation, with no evidence of parasites or neoplastic cells. The subcutaneous oedema initially improved with oxygen supplementation and furosemide therapy, but became refractory to treatment despite increasing doses. Humane euthanasia was elected after 2 days due to deteriorating condition. Postmortem examination revealed significant cachexia and oedema of the inguinal region and pelvic limbs without other macroscopic abnormalities. Histopathological analysis demonstrated diffuse and multifocal myocardial and renal lymphoma of high malignancy. Pulmonary and hepatic congestion with lymphoplasmacytic infiltration were also identified. This case illustrates an unusual presentation of extranodal lymphoma involving the heart and kidneys, highlighting diagnostic challenges and the potential role of myocardial infiltration in the pathogenesis of systemic oedema.
Schlax et al. (Fri,) studied this question.